反应详情

423 g of ethyl 3-chloro-5-trifluoromethyl-2-pyridinecarboxylate (Example H2) is initially introduced into a mixture of 800 ml of water and 160 ml of ethanol. 800 ml of a 2N sodium hydroxide solution are added dropwise at a temperature below 35° C. After 3 hours, the mixture is washed twice with methylene chloride and then rendered acid with an excess of concentrated hydrochloric acid, while cooling in an ice-bath. The slurry formed is filtered and the solid is washed with water and dried in vacuo. 318 g of the desired product are obtained as a white solid of melting point 135° C. (decomposition).

1. washthe mixture is washed twice with methylene chloride
2. temperaturewhile cooling in an ice-bath
3. customThe slurry formed
4. filtrationis filtered
5. washthe solid is washed with water
6. customdried in vacuo